Household refrigerator including automatic icemaker and control means therefor



July 2. 1968 R. B GELBARD 3,390,718

HOUSEHOLD REFRIGERATOR mcwnme AUTOMATIC ICEMAKER AND CONTROL MEANS THEREFOR Filed March 27, 1967 INVENTOR ROBERT B GEL BARD R FIGB y H\S ATTORNEY United States Patent 01 itice 3,3,7i8 Patented July 2, 1968 ABSTRACT OF THE DISCLOSURE A refrigerator comprising a fresh food compartment, and automatic icemaker and a refrigeration system for maintaining the compartment and icemaker at the required operating temperatures. The refrigeration system operates intermittently to maintain the desired fresh food compartment temperatures and electric lamp in the fresh food compartment is energized to increase the system operating time whenever the icemaker control calls for the production of ice Background of the invention Many modern refrigerators include a freezer compartment, a fresh food storage compartment and refrigerating means including a refrigerant compressor for operating the compartments respectively at below and above freezing temperatures. The compressor is cycled on and off in accordance with the cooling requirements of the fresh food compartment in order to maintain that compartment within a predetermined above-freezing temperature range. When such refrigerators also include an automatic icemaker disposed in the freezer compartment, the full potential daily icemaking capacity of the icemaker is seldom realized due to the fact that under normal thermal loads in the fresh food compartment, the refrigerator compressor is off a large percentage of the time. If the controls are arranged to turn the compressor continuously on to satisfy the icemaking requirements of the icemaker, undesirable low or freezing fresh food compartment temperatures may result. In the operation of a two temperature refrigerator of the type in which the two compartments are maintained within desired temperature limits by the circulation of refrigerated air from a single evaporator through the two compartments, this result can be avoided by decreasing the air flow to the fresh food compartment during icemaking periods but to do this relatively expensive air flow control means are required.

The present invention has as it primary object the provision of a combination refrigerator including an automatic icemaker within the freezer compartment and means for providing for maximum ice capacity by imposing an artificial heat load on the fresh food compartment whenever there is a call for the production of ice pieces by the icemaker,

Summary of the invention In accordance with the present invention there is provided a combination refrigerator comprising a freezer compartment, a fresh food compartment and an icemaker in the freezer compartment including a storage bin for receiving and storing ice pieces produced by the icemaker. The cycling of the compressor compartment of refrigerating means designed to maintain the two compartments at their respective operating temperatures is controlled by the temperature of the fresh food compartment. In order to operate the icemaker continuously for the production of ice pieces whenever the storage receptacle or bin is not full, means are provided for imposing an artificial heat load on the fresh food compartment. In accordance with the preferred embodiment of the invention, this artificial heat load is obtained by energizing the electric lamp normally provided for lighting the interior of the fresh food compartment.

Brief description of the drawing In the accompanying drawing:

FIGURE 1 is a side elevational view, in section, of one type of combination refrigerator incorporating the present invention;

FIGURE2 is a schematic diagram of that part of a refrigerator control circuitry designed to attain the objects of the present invention; and

FIGURE 3 is a graph illustrating how the normal cycle of operation of the compressor component of the refrigerator is altered in accordance with the operating requirements of the icemaker.

Description of the preferred embodiment While the present invention may also be applied to a combination or two temperature refrigerator in which the freezer and fresh food compartments are operated at desired below and above freezing temperatures by supplying to the two compartments streams of refrigerated air so proportioned that the desired temperatures are maintained in each of the compartments, it will be particularly described with reference to a two temperature refrigerator of the type in which the two compartments are cooled directly by separate evaporators mounted in each of the compartments and forming part of a refrigeration system including a refrigerant compressor.

A refrigerator of this type is illustrated in FIGURE 1 of the drawing as comprising a freezer compartment 1 maintained at below freezing temperatures by means of an evaporator 2 and a fresh food compartment 3 maintained at 'above freezing temperatures as for example within the range of 35 to 40 F. by an evaporator 4 which in itself cycles between below and above freezing temperatures. These evaporators 2 and 4 normally form part of a closed refrigeration system including a compresor 5 and a condenser 6 connected in closed series refrigerant flow connection. The output of the refrigeration system is controlled by cycling the compressor on and off by means of a thermostat 7 positioned within and responsive to the temperature within the fresh food compartment 3 so as to maintain the fresh food compartment temperatures within the above mentioned range.

An automatic icemaker of any of the well known types designed for the automatic production of ice pieces is disposed in the freezer compartment 1. The illustrated icemaker, generally indicated by the numeral 11 is of the type described and claimed in Shaw Patent 3,163,018, issued Dec. 29, 1964 and now assigned to the same assignee as the present invention. Such an icemaker, in addition to control means for controlling the periodic introduction of water into the icemaker mold and the periodic discharge of ice pieces from the mold includes a feeler arm 12 designed to sense the accumulation of ice pieces in a receptacle 14 and to stop the operation of the icemaker when the amount of ice collected in the receptacle reaches a predetermined maximum. To this end a pivoted feeler arm 12 has associated therewith a switch mechanism 15 which stops the ice maker when the bin is filled. In accordance with the present invention this switch 15, not only controls the operation of the icemaker but also controls the operation of additional components of the refrigeration system under certain conditionsu As has been previously indicated, the ice production rate for an automatic icemaker disposed in the freezer compartment of a household refrigerator is a function of the temperature of the freezer compartment. For

maximum ice rate, the temperature within the freezer compartment should be maintained as low as possible.

In accordance With the present invention a lower average operating temperature and hence a higher ice production rate for an icemaker operating within the freezer compartment is obtained by providing an artificial heat load in the fresh food compartment during periods when the feeler arm 12 and switch means 15 call for the production of ice.

While this artificial heat load may be provided by any electrically energized heating means disposed within the fresh food compartment 3 where the load provided thereby will be sensed by the thermostat 7, in accordance with the preferred embodiment of the present invention, this additional heat load is obtained by lighting an electric lamp 17 normally provided within the fresh food compartment 3 for illuminating the interior thereof.

The essential control circuitry for controlling the operation of the refrigerator in accordance with the present invention is shown in FIGURE 2 of the drawing. This circuitry includes a pair of supply lines 29 and 21 for supplying electrical power to the refrigerator. The icemaker 11 is connected across the supply lines 20 and 21 through the feeler arm switch 15 which is closed for continuously energizing the icemaker whenever the accumulated ice in the bin 14 is below a predetermined amount. When the sensing arm 12 senses the accumulation of a predetermined maximum amount'of ice in the bin 14, the arm 12 serves to open the switch 15 and de-energizes the icemaker.

In accordance with the usual practice, the compressor is also connected across the supply lines 20, 21 through the thermostat 7. For the purposes of the present invention the thermostat 7 is a single pole double throw switch and includes a first contact 23 which, when engaged by the switch arm 24 upon an increase in temperature within the fresh food compartment to a predetermined maximum, closes a circuit for energizing the compressor 5. The on cycle for the compressor is terminated when a predetermined low temperature within the fresh food compartment 3 is sensed by the thermostat 7 whereupon the switch arm 24 moves out of engagement with the contact 23 and into engagement with the contact 25 form-- ing part of a heating means control circuit including the lamp 17 and the feeler arm switch 15. If the feeler arm switch is closed, the lamp 17 is connected across the lines and 21 through the feeler arm 15 and contact of the thermostat 7. This circuit preferably also includes the switch arm 26 and contact 27 of door operated switch means 28. The switch means 28 also includes a switch contact 29 adapted to be engaged by the switch arm 26 and also a second switch including an arm 30 and a single contact 31. The switch arms 26 and 30 are interconnected by the action of the door so that the lamp 17 is energized to light the interior of the compartment 3 whenever the door is opened by engagement of these switch arms with the contacts 29 and 31 thereby connecting the lamp 17 directly across the lines 20 and 21 regardless of the positions of switches 7 and 15. Switch arms 26 and 30 may be interconnected components of a single switch assembly or components of two separate door-operated switches. When the door is closed, switch arm 26 engages contact 27 so that energization of the lamp 17 is controlled by the feeler arm switch 15.

The additional cooling, or in other words the increased icemaking rate, obtained by energizing the lamp 17 when the feeler arm switch 15 calls for the production of ice is illustrated in FIGURE 3 of the drawing. The upper curve A illustrates the cycling operation or energization of the compressor under normal operating conditions within the refrigerator, that is under conditions in which the icemaker is not energized for the production of ice. Starting at the left end of this curve, it will be seen that as temperature within the fresh food compartment 3 rises from a low of 35 to an upper limit of F., a compressor on cycle is initiated and the compressor continues to run until the temperature sensed by the thermostat 7 again reaches the lower temperature of 35 F. The compressor is then deenergized. The off and on cycles are repeated more or less regularly excepting when an additional load may be imposed as a result of door openings.

The lower curve B illustrates the cyclic operation of the compressor during periods when the switch 15 is closed to energize both the icemaker and the heating means or lamp 17. The heat introduced into the compartment 3 as a result of the lighting of the lamp 17 imposes an additional heat load with the result that the temperature rises more quickly from the low of 35 to the high of 40 during the off cycle and the compressor must operate for a longer on cycle in order to compensate for the continuous additional heat load of the lamp 17. As a result, the compressor operation comprises shorter off cycles and longer on cycles and as a direct result additional refrigeration is supplied to the freezer compartment by the evaporator so that it operates at a lower temperature and hence provides a greater cooling capacity for an increased rate of production of ice by the icemaker 11.

A particular advantage of the present invention is that the additional icemaking capacity is attained without affecting the actual temperatures maintained within the fresh food compartment 3. In other words, the fresh food compartment temperature is maintained above the minimum of 35 F. under all conditions so that freezing of the contents thereof cannot take place during the time that the compressor operates with the shorter off and longer on cycles.

While the invention has been described with reference to the particular type of combination refrigerator, it will be understood that it is not limited thereto but is applicable to any combination refrigerator in which the refrigerating means is controlled by the cooling requirements of the fresh food compartment.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a refrigerator comprising a freezer compartment, a fresh food compartment, and an icemaker in said freezer compartment inclding a storage bin for receiving and storing ice pieces produced by said icemaker;

refrigerating means for refrigerating both of said compartments,

electrically operated heating means in said fresh food compartment,

electrical control means for controlling the operation of said icemaker comprising an icemaker control switch means movable between a first position when the ice in said bin is below a predetermined amount and a second position when the ice in said bin is above said amount,

control means for cycling the operation of'said refrigerating means in response to temperature changes in said fresh food compartment,

and means for energizing said heating means when said icemaker control switch means is in its first position.

2. The refrigerator of claim 1 in which said heating means is an electric lamp.

3. In a refrigerator comprising a freezer compartment, a fresh food compartment, and an icemaker in said freezer compartment including a storage bin for receiving and storing ice pieces produced by said icemaker;

refrigerating means for refrigerating both of said compartments,

electrically operated heating means in said fresh food compartment,

electrical control means for controlling the operation of said icemaker comprising an icemaker control switch means movable between a first position when the ice in said bin is below a predetermined amount and a second position when the ice in said bin is above said amount, thermal switch means responsive to the temperature in said fresh food compartment and movable to a first operation position when the temperature in said fresh food compartment rises above a predetermined point to operate said refrigerating means and a second operating position when the temperature in said fresh food compartment falls below a second predetermined point to inactivate said refrigerating means, a heater control circuit including said icemaker control switch means and said thermal switch means for energizing said heating means when said thermal switch means is in its second position and said icemaker control switch means is in its first position. 4. The refrigerator of claim 3 in which said heating means comprises an electric lamp adapted to illuminate and heat the interior of said fresh food compartment.

References Cited UNITED STATES PATENTS 2,724,577 11/1955 Murphy 1653O 3,144,078 8/1964 Morton et al. 62-344 X 3,327,493 6/1967 Jacobus 62-137 ROBERT A. OLEARY, Primary Examiner.

W. E. WAYNER, Assistant Examiner. 

